Process of forming a casing for a rocket charge



Oct. 16, 1956 M. H. FARBER ETAL 2,766,507

PROCESS OF FORMING A CASING FOR A ROCKET CHARGE Filed Aug. 15, 1952 iliflilltr I I IN VEN TOR. 1135a;

ATTORNEYS.

Uflitd StEItCS Pate m 2,766,507 PROCESS on FORMING A essme so'Raa ROCKET CHARGE ApplicallonAngnst 15, l952;SerlaIFNo. 616 l'claim. c1. sip-1m The present invention'relatesto shovel and improved sha eii charge'especialiy ahapted forr'ocket propulsion.

Objects andtadvanta'ges lof the-invention will be set forth in part-hereinafter and-in part-wilhbe pbviouaherefrom,orimay .be learned by,practice withithe invention, the same being realized and attaincd by rneans o f 'the combination, steps and article pointed out in the appended claim.

The invention consists in the novel combination, steps and article and improvements herein shown and described.

The accompanying drawings, referred to herein and constituting a part hereof, illustrate one embodiment of the invention, and together with the description, serve to explain the principles of the invention.

Of the drawings:

Figures 1, 3, 4, 6, and 7 are fragmentary sectional views which illustrate successive steps in the formation of a shaped charge container especially adapted for rocket propulsion;

Figure 2 is an end view of the part shown in Figure 1;

Figure 5 is a sectional view of a ring insert; and

Figure 8 is a side elevation partially in section and showing the shaped charge container prior to loading.

The present invention has for its object the provision of a rocket propelled explosive container which can be used to produce a projectile of improved accuracy, greater reliability and increased penetrating power. A further object is the provision of such a container or projectile head which can be manufactured more rapidly and at less cost than the corresponding structures now manufactured and used.

in accordance with the present invention, the projectile head, explosive or shaped-charge container adapted for rocket propulsion is drawn from sheet metal stock, and is provided at its rear end with a threaded aperture, forming by turning or rolling over the sheet metal stock about a filler or strengthening ring, the layers'of metal at the aperture being brazed together and the aperture being internally threaded for attachment to the propulsion rocket. The drawn metal container or shell is of substantially uniform thickness, and the drawing operation is controlled to'maintain the metal of uniform thickness circumferentially of the shell. On the interior of the shell may be provided the usual shaped charge cone of metal, which is held to close tolerance of thickness and prior to loading, the interior of the shell is painted with a layer of protective paint care being taken to avoid paint being applied to the surface of the cone. The forward end of the drawn shell member is machined to provide a shoulder which receives the correspondingly machlned edges of s drawn-sheet metal ogive which is likewise held to close tolerances of thickness so that the entire assembled head is balanced about its longitudinal axis. After the explosive or shaped charged container and ogive have been brazed together, the container is loaded with the required amount of explosive and is then Patented Oct. 1-6, 4956 --scriptionand the following detailed description as well are exemplary and explanatory of the invention but are not restrictive thereof.

Referring now in detail to;-the.present preferred-embodiment of' the invention-and the steps-employedin its manufacture, as 'shown' in I the accompanying drawings, ra circular= disc of mild steel of the required 1 diameter "and held to close tolerances in its thickness is first cold-drawn to: provide -a body having a .generally cylindrical portion l0=of-the desired -diameterand-a :generally conical portion-12 which terminates in-a e1osed-end-14 -of'relatively smalldiameter, as -shown;i n }Figure -1. -In a second stage of cold drawing, the conical-portion 12 is further extended to increaseits taper, while the closed end portion 14 is slightly dishd-and furtherforme d tqprovide a r-internal grooved portion-16 and a cylindrical -heck .porti on -18 where-the 'closed;end- 14=joins the conical.portion. 12, as shown in Figure 3. r

The major portion of the closed end 14 is then punched out to provide an aperture 20, as shown in Figure 4.

Figure 5 illustrates a filler or strengthening ring 22 which is coiled to a circular form from a previously shaped bar of steel, the bar being cut to the correct length so that when it is circularly coiled, its ends are closely adjacent each other. As will be seen from Figure 5, the upper or forward edge of the ring 22 is inwardly chamfered, as at 24, to provide a substantial bevelled edge.

Ring 22 is then positioned in the neck portion 18 and is seated in the groove 16, and as shown in Figure 6, the remainder of the closed end 14 is turned or rolled inwardly and around the ring 22 until the inturned neck portion 26, the ring 22 and the neck portion 18 are in clos and intimate contact with each other.

The rolling operation is then continued until the forward edge of the inturned neck portion 26 is outwardly flanged around the bevelled edge 24 and tightly brought against the ring 22 so that the ring is secured in place, as shown in Figure 7. Thereafter, the parts 18, 22 and 26 are soldered, preferably by silver brazing, to join them into a unitary metallic structure.

After brazing, the interior of the inturned neck flange 26 is threaded, as at 29, with the appropriate thread for attachment to the forward end of a rocket motor. The forward end of the container 10 is then trimmed and machined to provide a shouldered rim 30 by which the container or shell body may be attached to an ogive.

The shell body is thus produced which has an exceedingly strong portion by which it is securely attached to the motor and there is little danger of this joint breaking during the firing operation.

lnteriorly of the shell or container, there is then probody 10 rearward of the cone 32 and the interior of the conical portion 12 are painted with a coat of protective paint 34, but'especial care is taken to avoid application of any paint to either surface of the cone 32, which would interfere with the uniform collapse of the cone 32 as it is melted and formed into a compact mass upon detonation of the charge which is loaded behind the cone and substantially fills the space within the shell body rearward of the cone.

3 The ogive 36 is also preferably formed of drawn sheet steel, in the general shape shown in Figure 8, and is pro vided at its rear end with ashouldered rim 38 by which it may be firmly joined and brazed or soldered to the shell body or container rim 30.

The finished shell or container thus provides two compartments, one bounded by the cylindrical shell 10 to the rear of the cone 32, the cone 32, the conical portion 12 and the threaded neck 29, while the other comprises the interior of the ogive 36, the cone 32 and the cylindrical portion 10 forward of the cone 32.

When the metal operations on the shells have been completed, the rear compartment is loaded with the required quantity of the desired explosive and with a suitable detonator.

The invention in its broader aspects is not limited to the specific combination, steps and article shown and described but departures may be made therefrom within the scope of the accompanying claim without departing from the principles of the invention and without sacrificing its chief advantages.

What is claimed is:

A process of forming a. casing for a rocket propelled charge from a sheet metal blank which comprises drawing the sheet metal to form a. small closed cylindrical end and a larger diameter cylindrical portion interconnected by an integral tapering portion,piercing the closed cylindrical end, positioning a ring within the small end, and inwardly turning the metal around the ring to tightly secure the ring between two layers of the sheet metal, brazing the ring to said layers and threading the interior of the inwardly turned metal to provide a rocket motor connection.

- References Cited in the file of this patent UNITED STATES PATENTS OTHER REFERENCES Elements of Ammunition, by T. C. Ohart. Copyright, 1946, by John Wiley and Sons, Inc., New York, New York; page 14. 

